Abstract : Phase interference filters are bridge networks in which the outputs of the bridge arms are summed to produce the desired filter effects. The following rates of decay were obtained in the magnitude characteristics by varying the pole locations of the transfer function: 12 decibels per octave when the poles were all real, 18 decibels per octave when one complex conjugate pair was located on a circle centered at the origin, 21 decibels per octave when one complex conjugate pair was located on an ellipse. Phase characteristics are determined and the low-pass filter is found to be linear phase up to nearly the half-power frequency. A transient response of the low-pass filter is conducted by analog simulation of the transfer function. A maximum of 10% overshoot is experienced when a complex conjugate pair of poles is located on a circle. The same method of analyzing the transfer function is applied to the high-pass filter with the following magnitude characteristics, 12 decibels per octave when all poles are real and 18 decibels per octave when a complex conjugate pair is located on a circle. A high-pass filter is then synthesized by these methods and tested. The half-power frequency is found to be in error by 1.6% and the cutoff frequency by 12% of the theoretical values. (Author)